Modular helmet

ABSTRACT

A simplified-fitting modular helmet resistant to aerodynamic stresses. The helmet has a base helmet and module, and includes between these two parts two lateral linking devices and an upper linking device. The linking devices include a finger secured to the module inserted into a socket secured to the base helmet and latchable in the assembled position of the helmet by a device of the quarter of a revolution type. The lateral fingers permit a small lateral clearance between the two parts of the helmet. Such a helmet may find particular application as an aircraft pilot helmet.

The present invention relates to a simplified-fitting modular helmetresistant to aerodynamic stresses, and in particular to a helmetintended for the pilots of warplanes.

The terminology “modular” signifies here that the helmet is of the typehaving two main subassemblies, namely a “base helmet” ensuring thephysiological protection of the user, and a “module”, overlying the basehelmet and ensuring several functions detailed hereinbelow.

The “base helmet” part ensures the following functions: retention of thehelmet (with the aid of a chinstrap for example), support for the audioequipment of the helmet, protection against knocks and againstperforation, support for the “module”, protection against fire, supportfor the oxygen mask, etc.

The module part supports, among other things, apparatus ensuring thefollowing functions: information presentation function (night visiongoggles, helmet viewfinder, etc.), function of gages (for exampleelectromagnetic sensor of head orientation, camera for restoring visualenvironment, etc.), miscellaneous functions (visor, hooding, etc.).

The advantage of a modular design such as this is that it is possible touse the base helmet (which can be customized) as a platform for fittingvarious modules as a function of the types of missions accomplished bythe user (day flight, night flight, reconnaissance, combat, etc.). Onthe other hand, the difficulties related to the use of this type ofhelmet on a fighter aircraft stem from the compromises to be made.Specifically, it is necessary to be able:

to accurately position the module with respect to the head of the userso that the visual information is presented to him in such a way as tocoincide with his visual axis;

to isolate the module (which is rigid for accuracy and stabilityreasons) from the base helmet (which is flexible, so as to be able to beeasily donned by the user and so as not to impede him);

to preserve the integrity of the helmet during a high speed ejection (upto 625 KEAS). This requirement is constraining, since the helmetviewfinders are characterized by visor positions which are very farforward and which increase the aerodynamic loads upon ejection;

to ensure ready modularity at the place of use, without any elementwhich may be lost, and which may be manipulated without tooling;

to obtain the lowest possible total mass. The known solutions do notfulfill all these conditions. Specifically, these solutions, which maybe classed into two groups, consist essentially:

either in strengthening the resistance of the module by adding materialto it, or in fixing the module on the base helmet by conventionalscrewing. These known solutions exhibit the following drawbacks:

the first makes the helmet very heavy and off-centered toward the front,and does not guarantee that the module will remain secured to the basehelmet which may deform under the effect of the “wind blast” when theuser ejects,

the second does not fulfill the requirements of isolation of the twoparts of the helmet and of non-use of tooling.

The subject of the present invention is a helmet of the aforesaid typewhich fulfills all the conditions set forth hereinabove and whose costprice is no higher than that of known helmets.

The helmet in accordance with the invention, of the type with basehelmet and module, comprises three linking devices between the basehelmet and the module, these linking devices taking the form of fingerssecured to the module and engaging in corresponding sockets of the basehelmet, two of these linking devices being disposed laterally andensuring a link with a longitudinal clearance and one being disposednear the apex of the helmet and ensuring a translationally fixed link.

The present invention will be better understood on reading the detaileddescription of an embodiment, taken by way of nonlimiting example andillustrated by the appended drawing, in which:

FIG. 1 is a simplified sectional view of a helmet assembled inaccordance with the invention,

FIG. 2 is a simplified sectional view of the helmet of FIG. 1, themodule being separated from the base helmet,

FIG. 3 is the same view as that of FIG. 1 illustrating a degree offreedom of the module with respect to the base helmet,

FIG. 4 is a partial sectional view of one of the linking devices betweenthe module and the base helmet according to the invention,

FIGS. 5 and 6 are perspective views of the linking device of FIG. 4,respectively in the disassembled state and in the assembled state,

FIG. 7 is a sectional view of the linking device of FIG. 4, butrepresented in a more complete manner, and

FIGS. 8 and 9 are perspective views according to two differentviewpoints of the module of the helmet of the invention showing, inparticular, the upper linking device respectively in the unlatchedposition and in the latched position.

Only the elements of the helmet which are necessary for an understandingof the invention have been represented in the various figures of thedrawing. Thus, for better legibility of these figures, neither elementssuch as the optical and optoelectronic apparatus (night vision goggles,viewfinder, etc.) fixed to the module, nor the various elements whichmay be fixed to the base helmet (chinstrap, audio equipment, oxygenmask, etc.) have been represented.

As represented in a very simplified manner in FIGS. 1 to 3, the helmet 1in accordance with the invention essentially comprises a base helmet 2in contact with the head of the user and a module 3 surrounding the basehelmet some distance from it and fixed to it with the aid of threelinking devices 4 to 6 which are secured to the module 3 and can beeasily assembled and disassembled relative to the base helmet 2. Thelinking devices 4 and 5 are disposed laterally, at the level of the axisof articulation of the visors of the helmet (clear visor and tintedvisor), have their axes concurrent and can be retracted outward. Thelinking device 6 is disposed at the apex of the helmet (or near thisapex). The linking devices 4 to 6, described in greater detailhereinbelow with reference to FIGS. 4 to 6, take the form of fingers 7to 9 engaging in bores of sockets 10 to 12 respectively, forming part ofthe base helmet 2. The fingers 7 and 8 can move in support mountings 13,14 fixed to the module 3, and can be latched in these mountings and inthe sockets 10 and 11 when the module 3 is in place on the base helmet,while nevertheless allowing a lateral clearance necessary for thedeformation of the base helmet relative to the module, as describedhereinbelow with reference to FIG. 4. The module is fitted onto the basehelmet simply by introducing the finger 9 into the bore of the socket12, the fingers 7 and 8 being retracted. Next, the module is correctlypositioned relative to the base helmet, in particular so that thefingers 7 and 8 are facing the bores of the sockets 10 and 11, and thesefingers are inserted while they are being latched in the insertedposition in the manner described hereinbelow.

As may be seen according to FIGS. 3 and 4, when the module 3 isassembled with the base helmet 2, and when the fingers 7 and 8 arelatched in the inserted position, a clearance remains between the moduleand the base helmet, this allowing a slight relative movement betweenthem in the direction marked “x” (direction parallel to the axis ofrotation of the visors), this ensuring the sought-after relativeindependence of these two parts of the helmet when they are assembled.Conversely, the finger 9 is translationally locked (as describedhereinbelow with reference to FIGS. 8 and 9), but can perform a slightrotation relative to the base helmet, about its axis.

However, such a characteristic does not guarantee the resistance of thehelmet to “wind blast” (relative wind when the user ejects from hisaircraft). Specifically, with the linking devices hereinabove, themodule, which is subjected to the major part of the aerodynamic loads(in particular on account of the visors, which have a relatively largesurface area), alone supports most of the loadings related to therelative wind during ejection. The principal behavior of the module isthen a lateral deformation and the module is subjected to a lifting loadtending to tear it off upward. According to the invention, so as not toincrease the mass of the module, these loads are transferred to the basehelmet (which is held on the head of the user by the chinstrap) so as torelieve this module. This is achieved by virtue of the fact that at theend of a short lateral travel in one or the opposite direction of themodule, one of the fingers 7 or 8 comes into abutment on the socket 10or 11, as illustrated in a simplified manner in FIG. 4. Represented inthis FIG. 4 is one of the lateral devices for linking between module andbase helmet, for example the device 4. Represented in this FIG. 4 is thesocket 10 fixed to the base helmet 2, the mounting 13 fixed to themodule 3 and the linking finger 7 (without its maneuvering knob, whichis represented in the subsequent figures).

The finger 7 has a body 15 in the form of a cylindrical rod which canmove in rotation and in translation in the mounting 13. That end of thebody 15 which is directed toward the outside of the module is slotted soas to make it possible to fix therein (see FIG. 7) the support bed 16 ofthe maneuvering knob 17 represented in FIGS. 5 and 6. The other end ofthe body 15 terminates in a head 18 of substantially hemisphericalshape, with a diameter greater than that of the body 15. Two mutuallyparallel flats 19, 20 are made on the surface of the hemisphere and thedistance between these flats is slightly greater than the diameter ofthe body 15. The head 18 is intended to be introduced into the socket 10and to be latched therein. Accordingly, the socket 10, which has anannular general shape, has an anterior part 21 (that facing the mounting13) exhibiting an opening with an oblong-shaped cross sectioncomplementary to that of the cross section of the head 18 (openinghaving a cross section with two parallel sides with separation equal tothat of the flats 19, 20 and terminating in arcs of a circle). Thebottom of the anterior part 21 consists of a transverse wall 22 drilledwith an opening 23 whose cross section has a shape complementary to thatof the cross section of the head 18. The body of the socket 10, to therear of the wall 22, is bored to a diameter substantially equal to thediameter of the head 18 before the formation of the flats.

Thus, to latch the finger 7 in the socket 10, the head 18 is introducedinto the opening of the part 21 while aligning the flats 19, 20 with theplane sides of the opening of the part 21, then inserting the head 18into the socket, and when the head 18 has negotiated the wall 22, it ismade to rotate by a quarter of a revolution. The head 18 can then nolonger be withdrawn from the socket 10 unless it is again made to rotateby a quarter of a revolution. As specified hereinabove, in order toallow the module a slight lateral play, there is provided a clearance oflength C1 of around 1 mm between the anterior edge of the head 18 andthe posterior edge of the wall 22 of the socket 10 (see FIG. 4) and aclearance C2 (of around 4 to 5 mm) between the apex of the head 18 andan abutment 10A fixed in the bottom of the socket 10, and likewise forthe linking device 5, when the module is fixed in place on the basehelmet. The length of the finger 7 and its travel are determined so asto make it possible to obtain the clearances of lengths C1 and C2. Theselateral play clearances allow the module to come very rapidly intocontact with the abutments of the helmet in the case of “wind blast”,and allow the user to “don” his helmet more easily on his head (the basehelmet being flexible). This lateral play clearance allows a greaterclearance, through a lever effect, at the level of the headphones of thehelmet (several cm), which are much lower than the axis of the fingers 7and 8.

The mounting 13, the bed 16 and the knob 17 are made in the mannerrepresented in FIGS. 5 and 6 in particular, so as to maneuver the finger7 and to lock its head in the latched position in the socket 10. The bed16 has a frustoconical general shape exhibiting, in succession along itsaxis, three different diameters. At its free end 24 (that which isdirected toward the outside of the helmet), the bed 16 exhibits itslargest diameter. A diametral channel 25 is made in the front face ofthe end 24, and it acts as housing for the knob 17 which is articulatedtherein. In the maneuvering position of the finger 7 (FIG. 5), the knob17 is folded down out of the channel 25 which it extends radiallyoutward from the bed. In the folded-up position (FIG. 6), the knob 17 ishoused in the channel 25. Only the free end 17A of this knob thenoverhangs radially from this channel, so as to enable it to be taken outof this channel. The knob 17 comprises a maneuvering tab 17B runningperpendicularly to the body of the knob near to the end 17A. The centralcross section of the bed 16 is that having the smallest diameter, andits other end 27 has a diameter intermediate between those of the othertwo parts of the bed. Two mutually parallel flats with one diameter aremade on this end 27 (only one of these two flats, referenced 27A, isvisible in FIG. 5).

Internally, the mounting 13, of annular general shape, comprises a dish28 whose inside diameter is equal to the outside diameter of the part 24of the bed 16 and whose depth is slightly less than the axial length ofthe part 24. A locating notch 29 serving as housing for the tab 17B ofthe knob 17 when the latter is folded up and when the head 18 is latchedin the socket 10 is made in the lateral wall of the dish 28. The wall 30of the bottom of the dish 28 is drilled with an opening whose crosssection has a shape complementary to that of the part 27 of the bed 16.The straight parts of the shape of this opening are oriented angularlyin such a way that when the part 27 enters this opening, the flats 19and 20 of the head 18 are parallel to the parallel sides of the opening23 of the socket 10, and that the head 18 can therefore be introducedinto the socket 10. The thickness of the wall 30 is equal to the axiallength of the groove 26 of the bed 16. The length of the body of thefinger 7 is such that when the part 24 of the bed 16 is in abutmentagainst the wall 30, the head 18 is completely engaged behind the wall22. To lock the finger 7, it is then sufficient to rotate it, with theaid of the knob 17, by a quarter of a revolution (in the clockwisedirection in the case of the initial position of introduction of FIG.5). After this rotation, the part 27 of the bed 16 is latched inlongitudinal translation by the wall 30, and the head 18 is latched inlongitudinal translation by the wall 22 while the knob 17 can be foldedup into the channel 25 and its tab 17B is housed in the notch 29,rotationally immobilizing the finger 7. Of course, the knob 17 isfurnished with appropriate means (for example a spring leaf) which holdit in the folded-up position, and which do not permit it to be foldeddown other than by the user when he pulls its end 17A.

According to an advantageous characteristic of the invention andillustrated in FIG. 7, abutments are fixed to the base helmet, near theends of the module and of the visors, at the level of the fingers 7 and8. Only the abutment 31 relating to the finger 8 has been represented.These abutments are in the shape of a stirrup with a “U” cross section.The abutment 31 is a device complementary to the abutment on the socket14 (see FIG. 7). Specifically, once the finger 8 has come into abutmenton the socket 14, the entire module can deform (under the effect of therelative wind during ejection) and hence give rise to moments on thefinger 8. Since the finger 8 is hemispherical, it does not adopt therotations and hence the rotational moments about the center of thesphere. This is why provision has been made for a second abutment withan offset axis which makes it possible to limit this rotation. Theabutment 31 is secured to the base helmet and is nonremovable. Themodule is fitted by firstly plugging in the central finger 9. Next, themodule is tilted backwards and the lateral mechanisms lodge behind theabutment 31. Next, the fingers 7 and 8 are inserted. These abutments 31are set in place automatically without impeding the fitting of themodule onto the base helmet.

Represented in FIGS. 8 and 9 is the control lever 32 of the upper finger9. A disk 33 comprising two mutually parallel peripheral flats is formedon the finger 9, under the lever 32. This disk 33 passes into an opening34 of corresponding shape made in the support 35 of the finger 9(support fixed on the module 3) when this finger is correctly orientedangularly and is inserted. When the finger 9 is in place, it is rotatedby a quarter of a revolution with the aid of the lever 32, and the disk33 becomes locked under the opening 34, in a similar manner to thelatching of the fingers 7 and 8. Of course, means (not represented) areprovided for rotationally immobilizing the finger 9, which means cannotbe unlocked other than by the user, so as to prevent any accidentalunlatching of the finger 9.

In the unlatched position of the finger 9, its lever 32 prevents thevisor from being raised (FIG. 8), it being possible to raise this visoronly when the finger 9 is latched (FIG. 9), thereby constituting asafety device which signals to the user that the module is not properlyassembled to the base helmet. This safety device is supplemented by thevisual indication afforded by the knobs 17 of the fingers 7 and 8: theseknobs can only be folded up and stowed in the channels 25 if the fingers7 and 8 are correctly latched in the sockets 10, 11.

As represented in particular in FIGS. 7 and 8, the axis of articulationof the visors can be concurrent with the common axis of the fingers 7and 8, thereby rendering the device of the invention compact. This makesit possible to transfer the aerodynamic loads applied to the visorsduring ejection to the base helmet by way of the fingers 7 and 8 withoutany mismatch, and hence to reduce the overall mass of the helmet.

What is claimed is:
 1. A simplified-fitting modular helmet, having aflexible base helmet for being fixed on the head of the user and a rigidmodule overlying the base helmet, comprising three linking devicesbetween the base helmet and the module, these linking devices taking theform of fingers secured to the module and engaging in correspondingsockets fixed to the base helmet, two of these linking devices beingdisposed laterally, and another being disposed near the apex of thehelmet, characterized in that the three linking devices comprise adevice for translational locking with respect to the rigid module, ofthe quarter of a revolution type, that the two lateral linking deviceseffect a link with longitudinal clearance, and that the third effects atranslationally fixed link.
 2. The helmet as claimed in claim 1,characterized in that the longitudinal clearance is around 1 mm in onedirection and around 4 to 5 mm in the opposite direction.
 3. The helmetas claimed in claim 1, characterized in that the ends of the lateralfingers comprise a device for translational locking of the quarter of arevolution type.
 4. The helmet as claimed in claim 1, characterized inthat in the unlatched position the upper finger completely preventsvisors of the helmet from being raised.
 5. The helmet as claimed inclaim 1, characterized in that in the latched position the fingers arerotationally immobilized.
 6. The helmet as claimed in claim 1,characterized in that it comprises two lateral fingers whose axes areconcurrent with those of visors.